The ocular zonule will be characterized in man and selected laboratory animals using morphological, immunohistochemical and chemical methods. The purpose is to classify the zonule as a structural protein, and to provide criteria for evaluating the zonule during aging, in the lens-dislocating diseases, and in normal accommodative function. Morphologic studies will be carried out with transmission and scanning electron microscopy and will include investigation of some of the conditions for zonular fibrillogenesis in animal eyes. Immunohistochemical studies will utilize the unlabeled antibody-enzyme technique for transmission electron microscopy. Chemical characterization of the zonule will include analyses of its amino acid, carbohydrate and peptide composition using standard methods. The effects of enzymes will be studied to illuminate both zonular microstructure and other possible avenues for zonulolysis. Special study will be made of zonular relationships of importance in cataract extraction and rhegmatogenous retinal detachment.